In the history of musical culture, romantic organs created in France in the 19th century are commonly called symphonic instruments. For French Baroque organs, called Classical organs – which to this day occupy a significant card in the history of organ building – symphonic instruments constituted an opposition pattern of construction, educated in the spirit of the aesthetics of the Romantic era. These instruments, being predominantly the works of one artist, Aristide Cavaillé-Coll (1811-1899), combine a repetitive structure of elements whose mutual relations influenced their individual tone. This structure of elements paved the way for many 19th-century organ composers and improvisers, and then created perspectives on 20th-century music. The legacy of French composers-improvisers associated with this particular type of organbuilding is a direct reflection of the features of these instruments. The literature on Aristide Cavaillé-Coll’s organist and organist is very rich. France has well-preserved archives, and the 19th century has already been a time of comprehensive use of permanent methods of recording both text and image (initially figures and then photographs). In addition, Cavaillé-Coll left many written materials – notes, scientific articles and other publications including illustrations; many non-existent instruments were sketched or photographed. First of all, many instruments have survived to this day, which are tangible proof of the features and skills of their author. The uniqueness of Aristide Cavaillé-Coll’s instruments and their influence on many phenomena of organ art caused and cause the development of many scientific studies. In this article I would like to show the evolution process of Cavaille-Coll’s symphonic organ throughout the whole life of this visionary organbuilder.